Precision fuel metering system



Nov. 26, 1968 E. D. LONG 3,412,718

PRECISION FUEL METERING SYSTEM FUEL PUMP W/ACCUMULATOR ACCUMULATORENGINE HEAD"\ -ts ELECTRONIC FROMfiTO E MODULATOR SUPPLY I ELEC. TRIGGERPOWER UNIT CAMSHAFT INVENTOR E. DAVID LONG BY (97.5 ab

ATTORNEY Nov. 26, 1968 E. D. LONG 3,412,718

PRECISION FUEL METERING SYSTEM Filed June 15, 1967 2 Sheets-Sheet 2 1INVENTOR E. DAVID LONG ATTORNEY United States Patent 3,412,718 PRECISIONFUEL METERING SYSTEM Emile David Long, Elmira, N.Y., assignor to GillettTool Co., Inc., Buffalo, N.Y. Filed lane 13, 1967, Ser. No. 650,563 8Claims. (Cl. 123-32) ABSTRACT OF THE DISCLOSURE A plurality of fuelmetering transducers are employed for simultaneously delivering measuredamounts of fuel to the cylinders of an internal combustion engine, onceper engine cycle, and in response to an electronic modulator whichsenses various engine operational and environmental parameters, such as,engine manifold air temperature and vacuum, engine temperature, enginespeed, throttle position and barometric pressure. Each of the fuelmetering transducers is mounted entirely within the engine air manifoldand adjustably positioned adjacent the respective inlet valve for eachcylinder, the fuel fed to each transducer being at constant pressure,whereby the measured amount of fuel being admitted to each cylinderdepends upon the length of time the transducer is held in open position.

Background of the invention Heretofore it has been the customarypractice to supply the proper fuel-air mixture to the cylinders of sparkignition internal combustion engines through carburetion wherein theliquid fuel is vaporized and mixed with air in the correct proportion.The use of carburetion in these engines has been nearly the universalpractice for economy and reliability in general day-to-day performance.While carburetor systems have been satisfactory for their intendedpurpose, they have been subject to certain disadvantages inherent intheir design. For instance, while trying to maintain the proper volumeand velocity of air flow to insure an adequate ratio of the fuel-airmixture, the fuel becomes deposited on the wall of the manifoldresulting in a reduction of fuel economy. Furthermore, in view of thefact that the heat of the manifold is utilized to facilitate thevaporization of the fuel, hot spots are formed in the manifold whichhave a tendency to cause backfiring and vapor lock.

In order to overcome the disadvantages experienced with carburetionsystems and in an attempt to provide a proper fuel-air mixture forcomplete combustion in the engine cylinder with a concomitant reductionof exhaust gases, it has been proposed to employ various types of fuelinjection systems. However, it has been found that designing a fuelinjection system for spark-ignition engines involves much more thanmerely substituting an injector valve for a carburetor. In bothmechanical and electrically controlled injection systems, the propercalibration and control of the fuel-air mixture through the full dynamicrange of the engine is most difiicult and sometimes impossible toachieve since the bellows, diaphragms and associated control linkagecommonly employed in these systems are frequently subject to binding,hysteresis and frequent malfunction.

While the shortcomings of known fuel injection systems have beenrecognized, the advantages of fuel injection over carburetion in sparkignition engines have equally been recognized by those skilled in theart. For instance, by eliminating the carburetor, the improved enginevolumetric efficiency and colder air charges results in an increase ofpower output at high engine speeds. Furthermore, the fuel-air mixturemore closely approaches a stoichiometric composition to thereby reducethe amount of unburned hydrocarbons and carbon monoxide in the exhaust.

Patented Nov. 26, 1968 Summary After considerable research andexperimentation, the fuel metering system of the present invention hasbeen devised to overcome the disadvantages experienced in fuel injectionsystems and comprises, essentially, a plurality of fuel meteringtransducers mounted entirely within an air chamber such as an engine airmanifold. Each of the transducers is adjustably positioned adjacent therespective inlet valve for each cylinder and includes an orifice offixed area which is opened and closed by an electromagnetically actuatedmember of fixed travel. The fuel metering transducers communicate with afuel rail which supplies fuel at constant pressure to the transducers,whereby the quantity of fuel admitted to the cylinders depends upon thelength of time the magnetically actuated members are held in openposition, the energization of the electro-magnet for each movable memberbeing controlled by an electronic modulator which senses various engineoperational and environmental parameters.

Brief description of the drawings FIGURE 1 is a diagrammatic view of thefuel metering system of the present invention;

FIGURE 2 is a fragmentary sectional view showing the position of a fuelmetering transducer relative to the engine cylinder;

FIGURE 3 is a fragmentary sectional view of the connection foradjustably positioning the fuel metering transducer within the enginemanifold;

FIGURE 4 is an enlarged longitudinal sectional view of the fuel meteringtransducer of the present invention;

FIGURE 5 is a view of the transducer taken along line 55 of FIGURE 4;

FIGURE 6 is a view taken along line 66 of FIG- URE 4;

FIGURE 7 is a view taken along line 77 of FIGURE 4; and

FIGURE 8 is a plan view of a modified form of a valve element adapted tobe employed in the fuel metering transducer of the present invention.

Description 07 the preferred embodiment Referring to the drawings andmore particularly to FIGURE 1, the precision fuel metering system inwhich the fuel metering transducers of the present invention are adaptedto be employed, comprises essentially, a fuel rail 1 for supplying fuelto a plurality of fuel metering transducers 2 adjustably mounted on theengine head by swivel joint connections 3, to be described more fullyhereinafter. The fuel supplied to be transducer through the fuel rail isfed thereto at constant pressure by a fuel pump connected to one end ofthe fuel rail and an accumulator at the opposite end thereof, saidaccumulator being of the type disclosed in my copending application Ser.No. 645,701, filed June 13, 1967. An electronic modulator of the typedescribed in my copending application Ser. No. 653,484, filed July 14,1967, is electrically connected to the transducer 2 for actuating thesame in response to various engine operational and environmentalparameters fed to the modulator by a throttle valve assembly and triggerunit. For example, the engine manifold air temperature and vacuum,barometric pressure and throttle position would be sensed by thethrottle valve assembly; and the trigger unit, actuated by the enginecam shaft, would sense the engine speed. When desirable, the triggerunit may be actuated by an electrical signal from the ignition system.The electronic modulator, in turn, feeds the transducers 2 with a squarewave pulse, the duration or width of which is a direct function of theintegrated valve of the various system sensors.

As will be seen in FIGURE 2, the engine upon which the fuel meteringtransducer 2 of the present invention is adapted to be mounted is aconventional internal combustion engine including an air intake manifold4, cylinder 5 and piston 6. Fuel taken into the cylinder through intakeport 7, controlled by valve 8, is ignited by spark plug 9.

Referring to FIGURES 4 to 7, the fuel metering transducer 2 of thepersent invention comprises a housing connected to the end of a fuelline 11 which is maintained in communication with the fuel rail 1(FIGURE 1). A solenoid is mounted within the housing and includes aninner pole piece member 12 and an outer pole piece member 13 surroundingand positioned concentrically with respect to the inner pole piecemember. A plastic spool 14 having an electrical coil 15 wound thereon issecured to the inner pole piece member, one end of the coilinterconnecting the pole piece members as at 16 and the opposite end ofthe coil being connected to a terminal 17 adhesively secured to theinner pole piece as at 18. A lead 19 is also connected to the terminal17 and extends upwardly within the fuel line 11 and is connected to aterminal 20 (FIGURE 3) secured to the Wall of the fuel line, theterminal 20, in turn, being electrically connected to the electronicmodulator (FIG- URE 1).

A nozzle 21 is rigidly secured within the lower end of housing 10 andsealed therein by an O-ring 22. A longitudinally extending, centrallydisposed orifice 23 is formed in the nozzle and communicates with arecess 24 formed by an annular shoulder or land member 25 disposed onthe upper surface of the nozzle and positioned concentrically withrespect to the orifice. The annular shoulder 25 forms a seat for aflapper valve 26 which is biased to closed position on the seat by acoil spring 27 having one end engaging the upper surface of the flappervalve and the opposite end engaging a shoulder 28 formed on the oppositeend portion of the housing. When the flapper valve is biased to closedposition on seat 25, there is a clearance of .004" between the end ofthe outer pole piece member 13 and the upper surface of the flappervalve; thus, when the solenoid is actuated, the flapper valve,functioning as an armature, is drawn upwardly a distance of .004"against the end of the outer pole piece. While in this position, thereis a .003" residual air gap between the end of the inner pole piecemember 12 and the upper surface of the flapper valve whereby an adequatemagnetic force may be generated in the solenoid. In order to provide ahydrostatic relief to thereby allow the flapper valve 26 to move freelybetween open and closed positions, apertures 13a and 26a are formed inthe lower end portion of the outer pole piece member and in the flappervalve, respectively.

In the operation of the fuel metering transducer, fuel, being fed underconstant pressure through fuel line 11, flows into the annular chamberdefined by the outer peripheral wall of the outer pole piece member 13and the inner peripheral wall of the housing 10. When a signal isreceived from the electronic modulator for actuating the solenoid, theflapper valve 26 is pulled upwardly from seat 25 thereby compressingspring 27 and allowing the fuel to flow into recess 24 and throughorifice 23 into the engine cylinder. When the solenoid is de-energized,the spring 27 expands forcing the flapper valve downwardly onto the seat25.

Since the fuel metering transducers are to be actuated once per enginecycle, the relatively small mass of the magnetically actuated flappervalve 26, moving through the fixed distance of .004" to open and closethe orifice 23 of fixed area, readily adapts the flapper valve foroperating speeds in the order of 1000 cycles per second, and since thefuel is being fed to the transducer at constant pressure, the quantityof {fuel admitted into the engine cylinder depends upon the length oftime the flapper valve is held in open position.

While the flapper valve shown in FIGURES 4 and 6 consists of a dischaving axially extending hydrostatic relief apertures formed in the bodyof the disc, another embodiment of the flapper valve is illustrated inFIG- URE 8 wherein the disc 29 is formed with a plurality ofcircumferentially spaced hydorstatic relief notches 29a formed in theperiphery thereof.

While the admission of the proper quantity of fuel to the enginecylinder in response to the engine speed and the absolute weight of theair charge is an important feature of the present invention, anotherequally important feature of the invention is the location of the fuelmetering transducer within the engine manifold to provide port injectionof the fuel to thereby prevent deposition of the fuel on the walls ofthe manifold while at the same time allowing proper vaporization of thefuel. In order to properly position each fuel transducer within themanifold, the swivel joint connection 3, as illustrated in FIGURE 3, isprovided, comprising a socket 30 mounted within the wall 4a of theengine air intake manifold; the socket being provided with a taperedbore 30a forming a divergent throat portion on one end thereof. Theopposite end of the socket has a threaded portion 30b for receiving asocket nut 31. The socket nut is also provided with a tapered bore 31a,similar to bore 30a formed in the socket, but diverging in an oppositedirection therefrom; the construction and arrangement of the divergentbores facilitating the later-a1 adjustment of the fuel line, to bedescribed more fully hereinafter. Seat portions 30c and 3112 are formedon the socket and nut, respectively, for accommodating a sphericalmember 32 through which the fuel line 11 is slidably mounted.

When mounting the fuel metering transducers on an engine, a plurality ofapertures are formed in the wall 4a of the manifold; and a fuel line 11,having a fuel metering transducer 2 secured to the end thereof, isinserted through each of the apertures, after which the socket 30 isslipped on the fuel line and swaged into the aperture. The sphericalmember 32 and socket nut 31 are similarly slipped on the fuel line andassume the position shown in FIGURE 3; however, before the nut 31 istightened, the fuel metering transducer is properly positioned relativeto its respective injection port by manually pushing the fuel linethrough the sphere 32 until the fuel metering transducer 2 touches thestem of valve 8. The fuel line and associated transducer is then backedoff slightly from the valve stem and adjusted laterally as shown indotted lines in FIGURE 3. When the proper position of the transducer hasbeen obtained, the nut 31 is tightened to thereby bind the sphere 32 onthe seats 30c and 31b. The spherical member 32 is formed from a suitableplastic, such as Teflon, which is characterized by its relatively lowcoeflicient of friction and sealant properties. Accordingly, by formingthe spherical member 32 from Teflon, the lateral and longitudinaladjustment of the fuel line and associated fuel metering transducer isnot only enhanced but also when the nut 31 is tightened, the Teflonsphere provides an excellent seal within the swivel joint connection.

The construction and arrangement of the fuel line 11, fuel meteringtransducer 2 and swivel joint connection 3 readily adapts the assemblyfor mounting on various types of conventional engines. While it has beenfound that the swivel joint connection, as described hereinabove, willgenerally accommodate adjustment of the fuel metering transducer, insome instances, it may be necessary to bend the end of the fuel line asshown in FIGURE 3.

From the above description, it will be appreciated by those skilled inthe art that the precision fuel metering system of the present inventionprovides a system having good cold starting and warm-up characteristics,good part throttle economy and good wide open throttle power; and sincevery few moving parts are employed, the system is not likely to get outof order even after long and continued use.

I claim:

1. In a fuel metering system for an internal combus tion engine whereinan electronic modulator is employed for actuating a fuel meteringtransducer in response to various engine operational and environmentalparameters, the improvement comprising, fuel metering transducer meansadjustably positioned within the injection port of the engine cylinder,and swivel joint means mounted on the wall of the engine air manifoldand connected to said fuel metering transducer means; said swivel jointmeans comprising, a socket mounted within the wall of the engine airintake manifold, a tapered bore formed in one end of said socket forminga divergent throat portion, a nut threadably mounted in the opposite endof said socket, a tapered bore formed in said nut forming a divergentthroat portion extending in a direction opposite to the throat portionformed in the socket, seat portions formed on the interior wall of saidsocket and on the end portion of the nut extending within the socket,and a spherical member mounted between said seat portions, said fueltransducer means including a fuel line slidably mounted within saidspherical member and extending through said divergent throat portions,whereby the position of the fuel metering transducer means may beadjusted relative to the injection port of the engine cylinder bymanually sliding the fuel line through the spherical member andswivelling the fuel line and associated spherical member to apredetermined position, said transducer means being held at thepredetermined position by tightening said nut to thereby bind thespherical members on said seat portions.

2. In a fuel metering system according to claim 1, wherein the fuelmetering transducer means comprises, a housing, a fuel line connected toone end of said housing, solenoid means mounted within said housing, anozzle rigidly connected to the opposite end of the housing and spacedfrom said solenoid means, said nozzle including a longitudinallyextending orifice formed therein, an annular land disposed on the inletend of the nozzle and positioned concentrically with respect to theorifice, a flapper valve positioned within said housing between thesolenoid and said land, and a coil spring surrounding said solenoidmeans and extending between the end of the housing and the flapper valvefor biasing the flapper valve against said land to close said nozzleorifice, said flapper valve being spaced from said solenoid means whenbiased to closed position, whereby when the solenoid is energized theflapper valve is drawn against said solenoid means to open said nozzleorifice.

3. In a fuel metering system according to claim 2, wherein the flappervalve comprises a disc having hydrostatic relief apertures formedtherein whereby the flapper valve may move freely between open andclosed positions.

4. In a fuel metering system according to claim 2, wherein the flappervalve comprises a disc having a plurality of circumferentially spacedhydrostatic relief notches formed in the periphery thereof, whereby theflapper valve may move freely between open and closed positions.

5. A fuel metering transducer comprising, a housing, a fuel lineconnected to one end of said housing, means operatively connected to thefuel line for supplying fuel at constant pressure to said housing,solenoid means having a core mounted within said housing, a nozzlerigidly connected to the opposite end of the housing and spaced fromsaid solenoid means, said nozzle including a centrally disposed,longitudinally extending orifice formed therein, an annular landdisposed on the inlet end of the nozzle and positioned concentricallywith respect to the orifice, a flapper valve positioned within saidhousing between the solenoid and said land, and a coil springsurrounding said solenoid means and extending between the end of thehousing and the flapper valve for biasing the flapper valve against saidland to close said nozzle orifice, said flapper valve being spaced fromthe core of said solenoid means when open and when biased to closedposition, whereby when the solenoid is energized the flapper valve isdrawn a fixed distance against said solenoid means to open the nozzleorifice of fixed area, thereby allowing the fuel to flow through saidnozzle orifice, the quantity of fuel discharged through the nozzleorifice depending upon the length of time the flapper valve is held inopen position.

6. A fuel metering transducer according to claim 5, wherein the flappervalve comprises a disc having hydrostatic relief apertures formedtherein whereby the flapper valve may move freely between open andclosed positions.

7. A fuel metering transducer according to claim 5, wherein the flappervalve comprises a disc having a plurality of circumferentially spacedhydrostatic relief notches formed in the periphery thereof, whereby theflapper valve may move freely between open and closed positions.

8. A fuel metering transducer according to claim 5 wherein said flappervalve is spaced from the solenoid means a distance of the order of .004when in closed position.

References Cited UNITED STATES PATENTS 1,025,884 5/1912 Schmitt 285-2,706,976 4/1955 Gianini 123139.17 2,856,910 10/1958 Goodridge.

2,859,741 11/1958 Gl nn 123139.17 3,032,025 5/1962 Long.

FOREIGN PATENTS 858,966 1/1961 Great Britain.

LAURENCE M. GOODRIDGE, Primary Examiner.

